1. Field of the Invention
The present invention relates to a radioactive isotope-labeled dye compound.
2. Description of the Prior Art
The present invention provides a dye which can be used in the field of marking a substance and identifying the substance, especially for a marking method for maintaining marking for a limited period of time to enable detection. A marking method comprising performing marking with a dye containing a radioisotope of an appropriate life, so that radiation then disappears after a certain period of time to leave a mark similar to those obtained with usual dyes, not only provides visible information, but also enables accurate recording of the mark over time progress, and therefore a wide range of uses thereof can be expected (WO2004/065134, the disclosure of which is expressly incorporated herein by reference in its entirety). Further, the dye can be expected to be used as a radioactive medicament (International Journal of Applied Radiation and Isotopes 34, 1383-1393, (1983), the disclosure of which is expressly incorporated herein by reference in its entirety).